Air separator



N0 7, 1.933- T. J. sTURTEvANT 1,933,604

AIR SEPARATOR Bij-mj my NOV- 7, 1933- T. J.' sTuRTEvANT 1,933,604

AIR SEPARATOR Filed July 14, 1930 3 Sheets-Sheet 2 IN VENT OR I TMW, ATTORNEY BM JMJ Nov. 7, 1933. T, J, STURTEVANT 1,933,604

AIR SEPARATOR Filed July 14, 1930 3 Sheets-Sheet 3 IN VENT OR Patented Nov. 7, 1933 AIR sErAnATon Thomas J. Sturtevant, Wellesley, Mass., assignor Y to Sturtevant Milll Company, Boston, Mass., a. corporation of Massachusetts Application July 14, 1930. Serial No. 467,716

5 Claims.' (Cl. 209-139) The invention to be hereinafter described relates to air separators for grading materials.

The invention is embodied in a separator of the type in which the classiiication is accomplished by an air current moving upward ina separating chamber and downward in a settling chamber. The air current is induced by a fan and caused to circulate through the chambers, and in its course passes through an inlet opening between the upper and lower shells forming the casing of the separating chamber. The materials to be graded are fed through a hopper into the separating chamber and are received by a rotary distributor which throws the materials out across the rising air current under the influence of centrifugal force. carried upward by the air current through an outlet opening over into the `settling chamber where they gravitate downward and are delivered therefrom, while the heavier particles or tailings gravitate downward through the rising air current in the separating chamber and are delivered therefrom.

As large a percentage as possible of fines of theV desired size should be separated from the tailings, but if the velocity of the upward component of the whirling Yair current is suiiiciently great thoroughly toclean such rines from the tailings, there is liability that tailings will be carried along with the fines from the separating chamber into the settling chamber. A purpose of the present invention therefore, is tok provide means which will obstruct passage of tailings from the separating chamber into the settling chamber, and permit the velocity of the upward component of the air current to be sufficiently high for more emcient separation of the rines from the tailings and greater capacity oi operation than heretofore possible in this class 'of work. To accomplish this, a rotary screen is provided in the separating chamber, and is so located with relation to the outletopening of said chamber as to 0bstruct passing of heavier particles through the outlet opening, anddeflect them toward the wall rof the separating chamber, where they may gravitate downward and be discharged. It is desirable that this separator shall b capable oi classifying various materials with different degrees of ineness of product. The size of the openings of the rotary screen is Xed.' Therefore, in order that within a limited range various .products may be obtained, provision is made for varying the inlet and outlet openings, thereby to control the velocity andyolume of the ail' Cr- The lighter Vparticles are culating through the chambers, the screen and the inlet and outlet openings. Y

As stated, the materials are fed into the separating chamber and received by a rotary distributor. It is desirable that materials shall be delivered from the distributor into several zones between the distributor and the wall of the 'separator, in order thatthe materials may be thoroughly disseminated Vin therising air current. The more the materials may fbe opened and vspread out, the more readily the classificationK4 will be accomplished. Another purpose of the present invention, therefore, is to'provide a` distributorwhich is designed to deliver materials from the perimeter thereof at varying distances from the axis of .rotation of the distributor, and

hence under varying degrees of vcentrifugal force.

The character of the invention may be best understood. by reference to the following description of an embodiment thereof shown in the accompanying-drawings, wherein:

Fig. 1 is a vvertical longitudinal section through an air separator embodying the invention;

Fig. 2 is a horizontal section taken on line 2 -2 of Fig. 1;

3 3 of Fig. 1 showing the under face of the combined baiiie and screen; Y

Fig. 4 is a vertical section taken on line 1 4 of Fig. 3; f,

Fig. 5 is a horizontal section taken on line 5--5 of Fig. 1; and

Fig.- 3 is a horizontalV section taken on line with an outlet opening 17 therein, and a conical shell 19 at the lower end thereof. l This inner casing is supported by brackets 21 between and secured to the drums 3 and 13.

Beneath and spaced from the conicalshell 19 is a conical shell 23provided with a discharge spout 25 which extends laterally through an opening in the cone 7 of the outer casing. The conical shell 23 is supported by plates 27 secured to angle bars 29 and 31 respectively secured to the cones 7 and 23.

In the inner casing is the separating chamber from without departing from the spirit and scope of the appended claims.

What is claimed is:

1. An air separator for grading materials comprising, in combination, separating and settling chambers having inlet and outlet openings between them, means to cause air to circulate and whirl through said chambers and openings and move up in the separating chamber and down in the settling chamber, a rotary distributor for delivering material to be graded into the path of the up-moving air in the separating chamber, a rotary baflie plate extending beneath the entire outlet opening, and a screen on said baffle plate extending from its periphery nearly to the wallof the separating chamber for obstructing passing of heavier particles through the outlet opening while permitting nes to pass through said opening.

2. An air separator for grading materials cornprising, in combination, separating and settling chambers having peripheral lower inlet and central upper outlet openings between them, means to cause air to circulate and whirl through said chambers and openings and move up in the separating chamber and down in the settling chamber, a shaft, a distributor and a solid plate on the shaft for baffling said outlet opening, and a screen ring rotating with the barile plate and located between its periphery and the wall of the separating chamber to lie outside of said central outlet opening for obstructing passing of heavier particles through the outlet opening while permitting nes to pass therethrough.

3. An air separator for grading materials comprising, in combination, separating and settling chambers having peripheral lower inlet and central upper outlet openings between them, means to cause air to circulate and Whirl through said chambers and openings and move up in the sepa-l rating chamber and down in the settling chamber, a shaft, a distributor and a central baiiie plate on the shaft Abelow said outlet and having a diameter at least equal to that of the outlet, and a screen ring on the edge ofl and rotating with the baffle plate and projecting therefrom toward the wall of the separating chamber, said ring being formed of sections.

4. An air separator for grading materials cornprising, in combination, separating and settling chambers lhaving peripheral lower inlet and central upper outlet openings between them, means to cause air to circulate and, whirl through said chambers and openings and move up in the separating chamber and down in the settling chamber, a shaft, a distributor and a central baflle plate on said shaft below said outlet, and a screen ring detachably connected to the baffle plate and projecting outward in substantially the plane thereof toward the wall of the separating chamber to lie outside of said central upper opening.

5. An air separator for grading materials cornprising, in combination, separating and settling chambers having inlet and outlet openings between them, means to cause air to circulate and whirl through said chambers and openings and move up in the separating chamber and down in the settling chamber, and a rotary distributor for delivering the material to be graded into the l path of the up-whirling air in the separating chamber under the influence of centrifugal force, said distributor having a polygonal perimeter, that the materials may leave the distributor at various distances from the center of the disl tributor and be delivered into differentzones in the separating chamber.

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